Electrical service providers such as electrical utilities employ electricity meters to monitor energy consumption by customers and other entities. Electricity meters track the amount of energy consumed by a load (e.g. the customer), typically measured in kilowatt-hours (“kwh”), at each customer's facility. The service provider uses the consumption information primarily for billing, but also for resource allocation planning and other purposes.
Many electricity meters employ digital circuitry to determine energy consumption and other billing values. For example, it is known to use digital signal processors to calculate energy consumption from digital energy measurement signals. The calculated consumption information is then displayed on a meter display. From time to time, a meter reader from the utility obtains the consumption information displayed on the customer's meter display to facilitate billing. In the alternative, or in addition, the meter may include transmission capabilities for transmitting consumption information to a remote utility computing device, thereby also facilitating billing.
Electrical power is transmitted and delivered to load in many forms. For example, electrical power may be delivered as polyphase wye-connected or delta-connected power or as single phase power. Such various forms are known as service types. Different standard electricity meter types, known as meter forms, are used to measure the power consumption for the various service types. The commonly used meter forms in the United States include those designated as 2S, 3S, 5S, 45S, 6S, 36S, 9S, 16S, 12S and 25S meter forms, which are well known in the art.
As discussed above, a primary purpose of metering is to determine energy usage by a load (customer) for the purposes of accurate billing. It is therefore known that tampering with an electricity meter can result in reduced billing charges, and stolen energy. Typical tampering techniques involve either disabling the meter itself, or bypassing the meter completely. Many types of tampering involve removal of the meter cover or removal of the meter itself. Removal of the meter cover, for example, can allow for disabling or adjustment of the meter circuitry. In some cases, the circuitry may be disabled and/or adjusted and the meter cover replaced in order to mask the tamper event.
To combat energy theft via tampering, it is known to provide mechanical switch mechanisms that are triggered by cover removal, meter removal, impact, and other common operations related to tampering. Such mechanical switches generate outputs that are detected by the meter processing circuitry, which may then record the event for display or transmission to the utility. Many of these methods, however, can be overcome via advanced mechanical skills and meter structural knowledge.
In many cases a meter can record or log a tamper event in an electronic memory, so that the service provider can obtain tampering information when it communicates with the meter. In a typical case, a technician from the service provider obtains tamper information from the meter via a communication port. The tampering issue can then be resolved and the event erased from memory. However, it has been determined in some regions that more and/or alternative means of detecting tampering should be employed, including that which may be carried out by service provider technicians.